Moving some drives from onboard SATA to HBA

Currently I have a TrueNAS CORE 13.0-U6.2 setup with 8 drives of a 2x6 Z2 on a LSI HBA and the other 4 drives on the onboard SATA controller along with a SSD mirror. The HBA drives are identified as da0…7 and the SATA as ada0,3,4,5.

What is the correct way to move these drives from the onboard SATA to an additional HBA?
One reason for wanting to do this is that, were I to upgrade or need to replace the ageing motherboard, any new motherboard may not have the same number of onboard ports.
Another reason is that, in the event of an upgrade, I may wish to use Proxmox as the base and virtualise the TrueNAS instance. Passing through HBAs is obviously easier.

TN shouldn’t complain if you just swap the disk, at least at cold.

Make sure to properly secure that. Passing through the HBA is NOT enough.